Modular heat installation for premises with water as a heat transmitting medium

ABSTRACT

A heat installation for buildings, with water as the heat transmitting medium which comprises a forward pipe and a return pipe (19 and 18 respectively) as well as radiators (11) connected to said pipes. Said installation is designed as a building element system and comprises differently designed buildings elements (1-10), which are strip- and block-shaped and can be inserted into each other and with which said forward pipe and said return pipe are integral parts. Said installation includes a main connection element (1), connection elements (2), inner corner and outer corner elements (3 and 4 respectively), threshold transition elements (5, 7), thresholds (6), radiator connection elements (8) and terminal parts (9). In a radiator connection element (8), like in the majority of the remaining elements, said pipes are arranged the one above the other, and through said element cylindrical cuts (51) extend, at right angles with said pipes, within the plane of said pipes and at a distance from each other in a horizontal direction, in which cuts inserts (54 and 55 respectively) can be introduced, one insert type (54) being designed for a one-pipe system and one of the radiator connection elements as regards said two-pipe-system respectively, while the other insert type is designed for a two-pipe-operation having a casing-like constriction element (66), which crosses the adjacent pipe (19) and ends in the other pipe (18). Said insert types can optionally be introduced into said cuts in order to allow a one-or-two pipe operation, also within the same installation.

The present invention relates to a heat installation for premises, waterbeing used as a heat transmitting medium.

Such conventional heat installations comprise loosely layed visiblepiping or piping accommodated in walls and floors respectively. Saidinstallations are designed throughout either as one- or astwo-pipe-systems. In all of the cases the installation has beenperformed by artisans with a manual individual pipe laying and assemblyoperation, which is very expensive and time-consuming. In case such asystem is to be installed in already finished houses, usually it isrequired that the floors and walls be torn open for an invisible pipelaying, or if the pipe laying is to be visible, said pipes willconstitute a strongly disturbing factor and also usually will emit heatin places where heat is not required, which to some extent is true asregards pipe laying in walls and floors, in which the heat insulation isunsatisfactory. Invisible pipe laying may involve risk of leakage, whichis hard to discover, with severe damages as a result, when leakage hasbeen discovered after usually an extended period of time, and thedevelopment of mould, rot and rust. Irrespective of whether aninstallation is done in connection with the erection of a building or inan already finished building painters, carpenters, floor-layers etc.have so far been required to be able to complete their work or else theywere required to perform additional work, when the installationcontractors have completed their work. The problem whether to select anone-pipe- or a two-pipe-system has also often been difficult to solve.One of the two systems may have been suitable for e.g. one specificmodule or building element, while the other one had been suitable forother modules. However, for practical reasons it has been necessary toconsistently select one single system and thus, one has been unable tocombine the two systems in a way which is advantageous for a partialarea. To let laymen install the heat system has been inconceivable andin certain countries not allowed, partly due to the above-mentioneddrawbacks and risks.

The object of the present invention is to suggest an improved heatinstallation, in which water is used as a heat transmission medium andwhich avoids the drawbacks mentioned above and promotes the state of theart in this field in various respects.

This object is attained by mainly designing an installation of the typeset forth above. Thanks to such a design it is very easy to use such asystem as a so called do-it-yourself installation, i.e. an installationdone by laymen, e.g. home and apartment owners. This system can easilybe delivered as a module system suitable for all conceivable sizes,designs and applications. Those buildings, in which the system is to beinstalled, advantageously can be completed, i.e. finish-painted andupholstered, provided with floor covering etc. before the systemaccording to the invention is to be installed. This means that thesystem according to the invention advantageously can be installed in newas well as in old buildings. When so called prefabricated houses areerected, it is not necessary to pay attention to the pipe laying andwall and floor elements can be provided even more finished than what hasbeen possible in certain cases so far. All kinds of pre-layout in thisrespect can be avoided and the house or apartment owner can himself to agreat extent select the design of the system or change the samesubsequently without any appreciable problems. Consequently, e.g. houseshaving electrical heat elements, which act directly, can in a quick,simple and inexpensive way be provided with a heat installation;according to the present invention with water as a heat transmittingmedium. Also, an installation according to the present invention doesnot require any closed so called loops. Thus, parts of the systemadvantageously can be installed as branches, which are terminated inoptional areas. In this way it is e.g. possible, in the way shown inFIG. 1 of the accompanying drawings, to lay one branch along one portionof a building, while another branch provides another portion of thebuilding with heat. Then said one branch can be designed as anone-pipe-system and the other branch as a two-pipe-system, and in thisway different heating requirements can be met in an optimal manner. Theproduction of the various components, which the system includes, can bedone in simple, fast and inexpensive ways due to a large scaleproduction, e.g. through casting or injecting molding of metallic andplastic materials respectively, starting with uniform modules forradiator connection elements, which subsequently can be easily andspecifically adapted for e.g. one- or two-pipe-operation and havingvarying choking/heat emission capacities respectively. In this way it iseasy to install radiators having an arbitrary size/heat emissioncapacity in arbitrarily selected areas and, if that is required, at thesame time select an adequate circulation of the heat medium through theradiator. This installation can easily be designed to smoothly and inprinciple without problems be passed by a door opening in a way that isset forth in the following description and the accompanying drawings,such an installation section preferably being designed as a threshold.It is then possible, in case this is required in a particular case, towithout problems obtain a reversal of the pipes, i.e. to let the forwardand return pipes change places, the upper pipe on one side of the dooropening becoming the bottom pipe on the other side. All the componentsin the installation can be designed to emit heat in an adequate manner,i.e. exactly with the heat emission and heat insulation which isrequired. This means e.g., that normally one tries to avoid a heatemission/heat losses, but that one, in order to avoid or counteract e.g.cold waves (kallras) below windows and along exterior walls, designssaid components to emit more heat by using less or no heat insulatingmaterial or by using additional heat emitting elements, which are knownper se, e.g. ribs, circulation openings etc. It is true that thebuilding itself, in which the system is to be installed, can becompleted and finished, when the system is to be installed, but thesystem itself and all the components included in it can of course becompleted and finished, e.g. painted, anodized etc. Any other tools thane.g. an adjustable wrench and a screw driver will not be required. It issufficient that the so called mains have been extended to a certainpoint, from which the system then can be installed, without requiringany expert work.

Additional characterizing features and advantages of the invention areset forth in the following description, reference being made to thedrawings, in which preferred although not limiting embodiments are shownand which include in more detail and partly schematically:

FIG. 1 a perspective view of a heat installation according to thepresent invention using water to transmit heat; FIG. 2 a main connectionelement (1) according to FIG. 1, shown in a) a sectional view, b) fromthe left and c) from the right in FIG. 1 FIG. 3 a connection element (2)according to FIG. 1, shown a) in a lateral or gable view and b) in aview from the

FIG. 2a is partial cross-sectional view of a main connection elementaccording to FIG. 1, FIG. 2b is a front elevational view of the mainconnection element, and FIG. 2c is a rear elevational view of the mainconnection element;

FIG. 3a is a cross-section view of a connection element and FIG. 3 is afront elevational view of the connection element;

FIG. 4a is a partial cross-sectional view of an innercorner element,FIG. 4b is an end view of an outer corner element, and FIG. 4c and FIG.4d show cross-sectional views of FIG. 4a and 4b, respectively;

FIGS. 4a and 5b show similar end views of a threshold transitionelement, FIG. 5c is a sectional view along line 5c --5c of FIG. 5a, FIG.5d is a sectional view along line 5d--5d of FIG. 5b FIG. 5e is asectional along 5e--5e of FIG. 5a and FIG. 5f is a perspective view ofthe threshold transition element;

FIG. 6a is a cross-sectional view of a first embodiment of a radiatorconnection element, FIG. 6b is a cross-sectional view of a secondembodiment of a radiator connection element, FIG. 6c is across-sectional view along section line 6c-6c of FIG. 6a showing theconnection of a radiator connection element, FIG. 6d is across-sectional view along section line 6d--6d of FIG. 6a showing theconnection of a radiator connection element, and FIG. 6e is a frontelevational view of the radiator connection element;

FIG. 7a is a front elevational view of a joint element showing its use,FIG. 7b is a cross-sectional view of the joint element, FIG. 7c is afront elevational view of a distant element, FIG. 7d, is a left endelevational view of the distant element of FIG. 7c, FIG. 7e is an endview of a cover element to spand the joints and FIG. 7f is across-sectional view of the cover element along section line 7f--7f ofFIG. 7e;

FIG. 8a is a cross-sectional view of a terminal part for a one pipesystem and FIG. 8b is a cross-sectional view of a terminal part for atwo pipe system.

In FIG. 1 a main connection element 1 is shown, which in a way known perse is designed to be connected to main pipings (not shown) to and frome.g. a central heater (not shown) and which is shown in more detail inFIG. 2. In FIG. 3 connection elements 2 are shown in more detail and inFIG. 4 inner corner elements 3 and outer corner elements 4 respectivelyare shown. Threshold transition elements 5 and 7 aremirror-symmetrically alike. Element 5 is shown in detail in FIG. 5. Athreshold 6 is disposed between such threshold transition elements. Aradiator connection element 8 is shown in detail in FIG. 6. Terminalparts 9 for blind loop ends are shown and in FIG. 7 a joint element 10is shown in detail, while in FIG. 1 radiators 11 are shown, which can beconventional hot water radiators having conventional radiator valves 12.

The heat installation shown in FIG. 1 is provided with two blindbranches, it being easy to design each branch, thanks to thecharacterizing features of the present invention, according toindividual needs at any time for an one-pipe-operation or atwo-pipe-operation. It is easy to design e.g. one of the branches forone-pipe-operation and the other for two-pipe-operation, there being noneed to make any exterior alterations. It is also possible, at any time,to add to the branches, i.e. extend them and/or mutually connect theirends. Also, it is easy to later on connect additional radiators and toremove existing radiators respectively from the system.

FIG. 1 shows clearly, that a heat installation according to theinvention advantageously can be designed as a basic module system orbuilding element system, selling the various components advantageouslybeing done in self-service outlets and an installation subsequentlybeing done by the buyer himself, e.g. a home or an apartment owner. Itis true that the majority of the components can be delivered in onesingle standard design as to dimensions, but it is easy to provideconnection elements 2 and thresholds 6 in various lengths, it therebybeing easy and simple to accommodate signs, particularly because theexact location of the various components per se easily can be adjustedwithin certain limits thanks to the insertion principle and the relativedisplaceability together with maintained functions for the rest whichresult from it.

Main connection element 1 shown in FIG. 2 comprises an arbitrarilydesigned strip- or block-shaped shell 13(which can be solid or hollowand be made of a plastic and/or metallic material having a front or roomside 14 and a rear or connection side 15, from which connection pieces16,17 project, which are placed on different levels and which areconnected at right angles to one return pipe and one forward (supply)pipe respectively namely pipe 18 and pipe 19 respectively, which extendthrough the main connection element in its longitudinal direction. Pipes18,19 are usually open in both directions, but in case just one branchis to issue from said main connection element, one of the end openingsof pipes 18,19 can be closed, e.g. plugged up. Front side 14 and upperside 20 of the main connection element can be decoratively designed inan arbitrary way, suitably in the same way and with the same profiledimensions as the following components, which are included in theinstallation. Pipe 18 is of course the feed pipe for hot water and pipe19 the return pipe for colder water. The upper pipe is e.g. the feedpipe. Main connection pieces 16,17 advantageously can compriseessentially tubular through elements (see FIG. 2a), which extend throughtransverse cuts (bores) in shell 13 and engage with closed ends havingflanges 21 in a somewhat broader recess 22 on the room-side of theshell, nipples 23 and 24 respectively being secured on ends, whichproject from the rear side of said pieces and e.g. are provided withexternal threads and which allow pieces 16,17 to be sealed against theshell, intermediate seals or the like being used. To this end thoseparts of the nipples which are placed adjacent the shell can e.g. have ahexagonal shape (see FIG. 2c). Within the area of pipes 18,19 saidpieces have transverse openings 82 and 83 respectively which correspondto the pipes, and location notches 84 of some type, which prevent arotation, can of course also be provided in an optional place. Theterminal areas of pipes 18,19 are, in a way which is shown in FIG. 4 andso forth, provided with circumferential internal grooves (not shown) and0-rings or the like introduced into said grooves.

Connection element 2, shown in FIG. 3, comprises a shell 25 comprisinge.g. a closed external housing 26, which accommodates ducts 27,28, onedisposed above the other, which are designed to function as a returnpipe and a forward pipe respectively and which project beyond the twoends of the shell in its longitudinal direction, e.g. differentdistances at the two sides, as shown in FIG. 3b, at least as regardselements adjacent a joint element to be described subsequently. Ducts27,28 can be integral with shell 25 by means of bridge portions 29according to FIG. 3a. Also, said shell can be provided with centraltransverse control elements 30 designed as holes and/or casings forscrews or the like, by means of which said elements can be fastened toe.g. a wall 81. Possibly with the exception of said control elements 30such a connection element can be made all of a piece, of a plasticand/or metallic material, e.g. aluminum, and remaining cavities canadvantageously be filled with an insulating material 31 in a way knownper se as regards the method. Also, ducts 27,28 according to FIG. 3a canbe designed solely as control elements, which possibly are not throughelements in their longitudinal direction and/or their circumferentialdirection, for separately introduced ducts, which possibly subsequentlycan be fastened to the shells, if that is desirable. In this way it iseasier to cut the connection elements to suitable lengths, withoutintroduced ducts, on the installation site, and ducts having the correctlengths can be introduced into said shells and in this way a notdesirable cutting of the ducts can be avoided. The duct ends areprovided with circumferential external bevellings 82.

In FIGS. 4a and 4c an inner corner element 32 is shown, legs 33,34 ofwhich suitably having the same external profile as said connectionelements and said main connection element. An outer corner element 35according to FIGS. 4b and 4d is designed in a similar fashion havinglegs 36 and 37 and the only difference between the two elements is thatthe room side, i.e. the possibly decorated side, in one of the cases isan inner corner and in the other case an outer corner. In the two casespipes 18,19 are disposed one above the other and their ends are providedwith circumferential grooves 38, in which O-rings or the like 39 areintroduced. Such corner elements are connected in a simple way toadjacent connection elements, the projecting duct ends of the latterbeing inserted in legs at least such a distance, that O-rings or thelike 39 are passed and in this way are expanded and consequently seal.Said corner elements can also be made in one piece of a plastic and/or ametallic material. They can be made hollow according to FIG. 3a orpossibly solid.

Threshold transition element 5, shown in FIG. 5, correspondsmirror-symmetrically to threshold transition element 7, and thus thelatter will not be shown or described in more detail. It is shown thatelement 5 has an upended (first) portion 40, similar to the componentsdescribed above and which changes into a horizontal (second) portion 41.The latter portion suitably is, as regards the external profile, similarto threshold 6, and in this way an adaptation to various thresholdprofiles can easily be done. It is shown in the various views in FIG. 5that upper pipe 19 changes via an obliquely downwardly directed passage42 into a lower extension of the same pipe, while lower pipe 18 via apassage 43, in an obliquely lateral direction, changes into a laterallyshifted extension of the same pipe. FIG. 5e shows that the two pipes18,19 are disposed within the horizontal threshold transition portion 41adjacent each other in the same horizontal plane. The same pipeorientation is used within threshold 6, not shown in detail, which thenis connected to the mirror-symmetrically designed threshold transitionelement 7, in which pipe 19 again being disposed on top within portion40 or possibly, if it is desirable in a special case, at the bottom,which is easily done e.g. if passage 42 does not extend in a verticalplane obliquely downwardly but obliquely downwardly in a lateraldirection in either element 5 or 7, while lower pipe 18 continuesstraight ahead, in which way a reversal can be attained, which howevernormally probably is not required. The end openings of pipes 18,19 are,in the same way as is shown in FIG. 4, provided with internal grooves 44and O-rings or the like 45 introduced in said grooves. Also, in requiredplaces possibly screwed plugs 46,47 can be used in order to renderpossible a chip removal machining operation or the like.

Radiator connection element 8, shown in FIG. 6, is mainly similar in itsdesign to the above-described elements and comprises a shell 48, whichaccommodates pipes 18,19, the end areas of which, in a way whichcorresponds to the above-described elements, are provided with internalgrooves 49 and O-rings or the like 50 introduced in said grooves. Inthis way connection elements 2 can be sealingly connected in the twodirections, and a longitudinal adjustment can thus be obtained. Startingfrom below two similar vertical cylindrical cuts 51 are disposed inshell 48, at a distance in a horizontal direction from each other ande.g. having a step-shaped expansion 52 at their lower ends and a similarconstriction 53 at their upper ends, from which said cut with itssmallest diameter extends outwardly through the upper side of shell 48.In each cut 51 an insert (member) 54 or 55 is introduced. Said insertshave a common principal design, namely a cylindrical body, whichessentially fills the respective cuts and has a lower flange 56 and 57respectively and an upper step-shaped end 58 and 59 respectively as wellas insert connection pieces 60 and 61 respectively, which projectthrough the upper cut opening. On said pieces, preferably provided withexternal threads, suitably nipples 62 can be screwed, which allow, viaseals or the like 63, a sealing against said shell and said insert aswell as a sealed engagement of said flanges 56,57 against the adjacentportion of said cut, preferably with intermediate seals or the like (notshown). Connection pipes 64 to a radiator 11 can then be connected tonipples 62 by means of nuts 65 in a way known per se.

Inserts 54,55 are provided with transverse openings, which correspond topipes 18 and 19 respectively. As regards first bore insert 54 suitablythere is a full equivalence, while as regards second bore insert 55 adirect connection between the radiator and pipe 18 via a closercasing-shaped passage 66 is intended as regards one of said radiatorconnections 64. Thus, this is the case with the radiator connectionelement according to FIG. 6a, which is designed for two-pipe (parallel)systems, in which one of said radiator connections 64 is entirelyconnected to pipe 19, while the other radiator connection 64 is entirelyconnected to pipe 18, pipe 19 being extended round the closercasing-shaped portion 66, which is shown in FIG. 6a and d. In order toavoid that casing-shaped portion 66 detrimentally influences the flowthrough pipe 19 laterally disposed recesses 67 are designed in insert55, which are shown in FIG. 6a and d. The material in shell 8 possiblycan also be reduced around casing-shaped portion 66, i.e. within thearea of upper pipe 19 around each cut 51, if that is required. Saidinserts are around their waist suitably provided with circumferentialgrooves 87 and O-rings or the like 88 introduced into said grooves.

The design according to FIG. 6b is used for one-pipe (series) system,two similarly designed inserts 54 suitably being introduced into cuts51, while the section of pipe 19 and/or possibly pipe 18 between saidinserts is provided with a choke element 68, which it is easy tointroduce in the respective pipes from either end, which choke elementis shaped like a casing, suitably provided with recessed ends andexternal circumferential O-ring 69, introduced into a groove 70, andsuitably in this way simultaneously an advantageous friction locking canbe obtained. This choke element has a passage with a reduced diameterand thus the first radiator connection, seen in the flow direction ofthe heat medium, is subjected to a higher pressure and consequently canfunction as an inlet, while the second radiator connection, subjected toa lower pressure, functions as an outlet. Of course, it is easilypossible to calibrate said choke elements differently, in which way asregards a series of radiator connection elements a choking according toe.g. a falling or rising scale can be obtained. Cuts 51 and/or inserts54,55 can be provided with rotation--preventing location notches, inorder to position the various pipe sections exactly on one line. Toprevent a rotation in this way is a method already known per se and thussuch notches are not shown in detail.

In FIG. 7 a joint element is shown, generally designated 10, whichpossibly is needed between two adjacent connection elements. Thiselement is provided with a shell 71 having pipes, grooves and O-ring orthe like according to the design illustrated above, and in order toaccommodate e.g. longer projecting pipes a distance element 72 having acentral recessed bore or the like 73, designed to introduce a mountingscrew, not shown, can be used. The material around bore 73 can beextended inwardly in order to form a location notch 74 designed to holdsaid pipes. The latter may in said joint elements, also as regards jointelements between other module elements 1-10, be surrounded by coverelements 75 having a wall 76, which surrounds said pipes, and anexternal joint lip 77, which covers said joint elements outwardly.

Finally in FIG. 8 terminal parts 9 are shown, namely one terminal partfor an one-pipe-system in FIG. 8a and one terminal part for atwo-pipe-system in FIG. 8b. The difference is that within the terminalpart for an one-pipe-system the two pipes 18,19 are connected to eachother through an and passage 78, while instead of such a passage a(partition) 79 is used in the terminal part for a two-pipe-system. Inthe two cases there are provided at the pipe inlets circumferentialrecessed grooves and O-rings or the like introduced in said grooves. Itis apparent, that the two terminal parts and the two designs allow blindterminal branches. The only difference is that in a two-pipe-systemalready in the first fed radiator the return water enters into thereturn piping, while a true return piping not starts until in theterminal part as regards a one-pipe-system.

The present invention is not limited to the embodiments described aboveand shown in the accompanying drawings but can be modified andsupplemented in an arbitrary manner within the scope of protection ofthe present inventive idea and of the following patent claims. All ofthe components can of course be provided with e.g. a covering shell ofsome kind of fine wood or of any other arbitrarily selected material andconfiguration, and possibly quick-locking means designed in a way knownper se can be used. Also, it is possible, according to the need, to makethe various modules more or less heat-insulating, which has been statedabove. The modules advantageously can be provided with at least oneextra through cavity in their longitudinal direction, e.g. in the formof a third and a fourth pipe or piping respectively, through whichcavities e.g. cooled or heated air can be transported or which can beused for wiring of e.g. electrical, tele- and/or communication wiresetc. Such additional cavities only result in a very small additionalcost and no extra work whatsoever during the installation work, sincethe same construction and assembly principle can be used as for thewater pipes. Also, in particular cases it is feasible to use an extracavity for a tap water pipe, the cavity itself being used as a tap waterpipe, or a hose, preferably made of a plastic material and inserted intothe cavity.

I claim:
 1. A heating system for building, using water as a heattransmitting medium, comprising two conduits (18, 19), one of which is asupply conduit and the other of which is a return conduit, and at leastone of the two conduits being connected with at least one radiator (11),characterized in that the heating system comprises a plurality ofdifferent modular building elements (1-10) interconnectable with oneanother to form a flow path for the water therethrough, and eachbuilding elements (1-10) has a said supply and a said return conduitsupported therein disposed adjacent and substantially parallel oneanother, wherein at least one of the building elements of the heatingsystem is a connection element (8) which connects the at least oneradiator (11) to the heating system, the connection element (8)comprises an elongate element carrying a said supply and a said returnconduit and having two spaced apart bores (51) extending therethrough atright angles to the two conduits and disposed within a plane defined bythe two conduits, a removable bore insert (54, 55) is positioned withineach bore (51) and each bore insert having two transverse openingstherethrough aligned with said supply and return conduits andinterconnects the at least one radiator with a desired one of the twoconduits of the connection element, and the bore inserts are removablefrom their respective bores, said bore inserts (54, 55) comprisingeither of identical bore inserts, each interconnecting the at least oneradiator with the same conduit, provided in the two bores of theconnection element (8) so that a series piping system is achieved ordissimilar bore inserts, each interconnecting the at least one radiatorwith a different one of the two conduits, provided in the two bores ofthe connection element (8) so that a parallel piping system is achieved.2. A heating system according to claim 1, wherein one of the buildingelements (1-10) is a connection element (1) having a shell (13) with twomain connection pieces (16, 17) projecting from a rear side (15) thereofin the same direction but at different levels spaced from one another, asaid return and a said supply conduits, respectively, extendlongitudinally through the connection element and each being connectedat a right angle with a different one of the two main connectionpieces;the main connection pieces (16, 17) comprise tubular elements,which extend through transverse bores in the shell (13) of theconnection element (1), one end of each main connecting piece (16, 17)is closed and carries a flange (21) which engages a recess (22) on afront side of the shell while the opposite end of each of the mainconnection pieces extends completely through and out of the transversebores and carries an external thread engageable by a thread memberwhereby the main connection pieces can be sealingly connect to the shellwith an intermediate seal (80) positioned therebetween.
 3. A heatingsystem according to claim 2, wherein a transverse opening (82 and 83respectively) is located adjacent the closed end of the main connectionpieces (16, 17) and the transverse opening of each of the mainconnection pieces communicates with the conduit (18 or 19) to which themain connection piece is connected, and location means (84) are providedon both the main connection pieces 16, 17) and the connection element(1) for insuring properly alignment of the transversed openings with adesired one of the two conduits.
 4. A heating system according to claim1, wherein at least one of the building elements (1-10) is a connectionelement (2) having a shell (25) which forms an external housing (26)containing a said supply and a said return conduits (27, 28) therein,opposed ends of the two conduits project outwardly in a longitudinaldirection disposed adjacent one another, the two conduits are connectedto the shell via bridge portions (29), the shell is provided with meansfor releasably fastening the connection element (2) to a desired object(81), a cavity is formed between the two conduits and the shell whichaccommodates an insulating material (31), and the opposed ends of eachconduit are provided with a circumferential external bevelling (82). 5.A heating system according to claim 1, wherein at least one of thebuilding elements (1-10) is an inner corner element (32) having two legs(33, 34) connected to one another at a right angle, each legaccommodating a said supply and a said return conduits therein, and endportions of each of the said supply and said return conduits remote fromthe right angle have a circumferential groove (38) formed thereinaccommodating a seal element (39).
 6. A heating system according toclaim 1, wherein at least one of the building elements (1-10) is anouter corner element (35) having two legs (36, 37) connected to oneanother at a right angle, each leg accommodating a said supply and asaid return conduits therein, and end portions of each of the saidsupply and said return conduits remote from the right angle have acircumferential groove (38) formed therein accommodating a seal element(39).
 7. A heating system according to claim 1, wherein at least two ofthe building element (1-10) are first and second transition element (5,7), the first transition element comprises a first portion (40)connected to a second portion (41) by a transition section, the firsttransition element accommodating a said supply and a said returnconduits therein, the said supply and said return conduits in the firstportion defining a first plane and said supply and said return conduitsin the second portion defining a second plane perpendicular to saidfirst plane with the transition section allowing transition of the saidsupply and said return conduits between the first and second portions,the opposed ends of the two conduits (18, 19) are provided with aninternal groove (44) accommodating a sealing element (45), and thesecond transition element is a mirror image to the first transitionelement.
 8. A heating system according to claim 1, wherein theconnection element (8) has a shell (48) and opposed end portions of eachof the two conduits are provided with an internal groove accommodating asealing element (50).
 9. A heating system according to claim 8, whereinthe bores (51) are each provided with a step-shaped expansion (52) atone end thereof and a step-shaped constriction (53) at the other endthereof which forms a smaller diameter opening in an upper surface ofthe shell (48), each bore insert essentially fills the respective boreand has a lower flange (56 and 57, respectively) engaging the expansionand an upper step-shaped end (58 and 59, respectively) engaging theconstriction and an insert connection piece (60 and 61, respectively)projecting out through the bore, each insert connection piece isprovided with an external thread engaged by a nipple (62) which, viaseal elements (63), allows a sealed engagement between the connectionelement and the bore insert.
 10. A heating system according to claim 9,wherein a connection element (64) of the at least one radiator (11) isconnected to the nipple (62).
 11. A heating system according to claim 1,wherein the bore inserts (54, 55) are each provided with at least onetransverse opening (85, 86) communicating with one of the two conduits(18, 19) and a central passage extending at least partially through thebore insert along a longitudinal axis defined by the bore insert and thecentral passage is connected with the transverse opening.
 12. A heatingsystem according to claim 1, wherein a first bore insert (54) has twospaced apart transverse openings (85, 86) which are located, when thebore insert is received within the bore, to communicate with the saidsupply and said return conduits (18, 19), respectively, and the centralpassage communicates only with the transverse opening communicating withthe said supply conduit, whereby when a said first bore insert (54) ispositioned in each of the bores (51) of the connection element (8) theseries system is achieved.
 13. A heat system according to claim 1,wherein a first bore insert (54) has two spaced apart transverseopenings (85, 86) which are located, when the bore insert is receivedwithin the bore, to communicate with the said supply and said returnconduits (18, 19(, respectively, and the central passage communicatesonly with the transverse opening communicating with the said supplyconduit and a second bore insert (55) is only provided with onetransverse opening and provides communication between the said returnconduit and the central passage but prevents communication between thesaid supply conduit and the central passage, whereby when the first andsecond bore inserts are positioned in the respective bores (51) of theconnection element (8) the parallel system is achieved.
 14. A heatsystem according to claim 1, wherein a choke element (68) is inserted inthe said supply conduit (19) of the connection element (8) of seriessystem, between the two bores.
 15. A heating system according to claim1, wherein at least one of the bores 51 is provided with rotation ofpreventing locational notches.
 16. A heat system according to claim 4,wherein at least one of the building elements (1-10) is a joint element(10) for interconnecting two adjacent connection elements (2), eachjoint element comprises a shell (71) containing a said supply and a saidreturn conduits (18, 19) and opposed ends of the said supply and saidreturn conduits having an internal groove accommodating a sealingelement, the joint element further comprises a distance element (72)having a central recessed bore (73) for accommodating a fasteningelement for fastening the joint element (10) to a desired object, andthe distance element (72) having location notches (74) on an interiorsurface thereof for locating and retaining the two conduits (27, 28).17. A heating system according to claim 16, wherein joints between otherbuilding elements (1-10) are provided with a cover element (75), havinga wall (76) which surrounds the two conduits (27, 28) and an externaljoint lip (77) which outwardly covers the joint.
 18. A heating systemaccording to claim 1, wherein at least one of the building elements(1-10) is a terminal part (9) for the series system which includes anend passage (78) interconnecting end portions of a said supply and asaid return conduits (18, 19) with one another within the terminal part,and a circumferential recessed groove accommodating a sealing element isformed in an end of each of the two conduits remote from the endpassage.
 19. A heat system according to claim 1, wherein at least one ofthe building elements (1-10) is a terminal part (9) for the parallelsystem in which end portions of a said supply and a said return conduits(18, 19) supported therein are sealed and separated from one another bya partition (79), and a circumferential recessed groove accommodating asealing element is formed in an end of each of the conduits remote fromthe partition.